Russia has banned a pro-democracy charity founded by hedge fund billionaire George Soros, saying the organization posed a threat to both state security and the Russian constitution.

In a statement released Monday morning, Russia's General Prosecutor's Office said two branches of Soros' charity network — the Open Society Foundations (OSF) and the Open Society Institute (OSI) — would be placed on a "stop list" of foreign non-governmental organizations whose activities have been deemed "undesirable" by the Russian state.